Step 1: Search Instructables
For me, the best part of Instructables is just pokin' around and finding things hidden all over the place. Exploration may not yield you the answer to your question, but you may learn something you never knew or find a project that tickles your fancy.
Step 2: Search the Internet
If you expect someone to spend a few minutes responding to your question, wouldn't you feel guilty if you hadn't even spent a little time yourself? It's just a courtesy thing.
Step 3: Ask an Answer
You have a question. You want an answer. To get said answer, you should make it as easy to answer you as possible. The Answer tool is set up for this! Amazing :D
When you activate the Answer tool, you'll notice two boxes. One is small and says "Your Question" and the other is big and says "Details." These both have distinct purposes.
Only put your question here. Succinct. KISS. We don't want a paragraph here. Just the question. If you have multiple questions, submit more Answers!
Here is where you 'splain yourself. Don't leave this blank and don't make it too stream-of-consciousness. Add any background information here that will help people answer your question. Some possible information to include:
Why are you asking this question?
What is the context of the question?
Do you have a budget?
Do you have a deadline?
What are the size restraints?
Do you already have materials?
What tools do you have?
The more information you provide, the more the answerers can determine if you've even asked the right question. I often ask questions about something of which I have little knowledge. And that's the point. We're all trying to learn. The experts can then come back and say "Well this is how it really is, so did you really mean to ask *this*?"
If you want the best answers, don't keep secrets. Let everyone in on your plans and get the collective creative juices flowing. Instructables has a very diverse and knowledgeable following, so tap into this resource and prepare for enlightenment.
With your text fields filled out, move on to the Categories and Tags. These are fairly straightforward.
If your question is mainly concerned with general knowledge, or even specific knowledge, then you may not need a picture. However, if you are dealing in tangibles and extremely specific processes or materials, you may want to show the world what you are working with instead of describing it all back-and-forth in the comments.
Step 4: Preview Your Answer (then Publish)
If you don't take your Answer seriously, nobody else will. For me, even a single typo in a one-sentence question ruins it. It only takes a second to correct mistakes! Save your typos for large paragraphs ;)
Even though Answers is a quick-and-dirty tool in a lot of ways, put a little love into it.
(I understand that not everyone has perfect command over the language, but it's fairly easy to tell the difference between someone who doesn't know the language and someone that is just lazy.)
Below are examples of both good and bad Answers. While the knowledge capturable in each may be just as important, the difference in presentation style makes quite a difference.
Step 5: Answering an Answer
There are tons of questions to sift through, so start with what you know. Try to find questions about which you know something so that your two cents are relevant. Humor is OK too -- regardless of relevance. In moderation.
Hopefully the person will have a nice, succinct, question in bold and a comprehensive Detail section that gives you enough background information. If they've been following this Instructable, they will already have done some sort of search of Instructables and the internet, so your job is to add what you know personally.
If your input is very similar to someone else's, I suggest using a Reply to that person's answer, so that it reinforces their comments and keeps topics grouped nicely. Feel free then to add your own take on things in a new comment (answer). Even if you don't really know a lot about the subject, it's perfectly ok just to throw a ton of ideas out there. Brainstorming answers collectively is an important part of the creative process, so get it all out of your noodle and onto the internet to let everyone dissect.
Step 6: Wisdom of the Masses
This Instructable shouldn't deter anyone from asking a question because they don't want to put time into it; rather, it should provide ideas on how to better communicate our ideas to others and use our resources effectively.